Actually, Use Anywhere You Would Use a Disposable Wax Tea Light Candle.

One of the best features is that you can control the height of the flame and the amount of heat just by increasing or decreasing the exposed with above the wick holder.

The oil candles are made of Hand-Blown Borosilicate Glass, which is like Pyrex and are simple to refill.

The Firefly Tealight Candle holds about 1/2 Ounce of Fuel.

Burn Time is VERY Dependent on the Type of Fuel You Purchase and the Height of the Wick. Therefore, in our experience, burn times range from 4 to 8+ hours. It's a wide range but we've done the testing with different lamp oils and flame heights.